fix(desktop): restore layout control hit targets

[juliusmarminge]

Electron 44 makes app-region inherit into header children. Later header rectangles cover the fixed layout buttons, leaving only their thin edges clickable.

Reset direct children of each drag region with -webkit-app-region: initial. This stops inherited rectangles from covering controls while preserving the parent titlebar's drag area. Explicit none is unsuitable here: Chromium converts it to no-drag, which removes the children's area from the draggable titlebar. The base-layer rule preserves explicit drag/no-drag utilities.

Validation:

• An isolated Electron 44.1.0 fixture confirms explicit none computes to no-drag, while initial computes to the neutral none state. The header retains drag and its button retains no-drag.
• The actual stylesheet compiles with the repository's Tailwind version. Formatting and whitespace checks pass.
• Fresh source audit found no issues; the diff is limited to the shared CSS rule.
• All executed CI checks pass. Macroscope approved the current commit and CodeRabbit found no actionable issues. Bugbot remains unavailable due to the team spending limit.
• Julius verified that the controls remain clickable and dragging empty titlebar space moves the window again with the corrected CSS. Julius is handling the interaction recording.

Closes #10661

Note

Fix drag-region hit targets by resetting -webkit-app-region for direct children

Adds a base-layer CSS rule in index.css that resets -webkit-app-region to its initial value for direct children of .drag-region. Existing unlayered selectors for buttons, inputs, textareas, selects, and links still mark those controls as no-drag and take precedence over the layered reset. This restores correct click behavior for layout controls inside frameless titlebar drag regions.

^{Macroscope summarized 7862a3c.}

Summary by CodeRabbit

• Bug Fixes
  • Improved title bar dragging behavior in the desktop app.
  • Interactive child elements now avoid unintentionally creating draggable areas while preserving explicit drag and no-drag controls.

Model: GPT-6. Harness: Codex.

[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

ℹ️ The exact PR base did not have a successful artifact. Baseline uses the latest successful main measurement shown below.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	11.3 KiB	13.6 KiB	+2.3 KiB (+20.3%)	15.1 KiB	✅
Codex	Thread snapshot wire	5.5 KiB	7.0 KiB	+1.6 KiB (+29.0%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	5.9 KiB	6.6 KiB	+730 B (+12.2%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	49.7 KiB	57.1 KiB	+7.3 KiB (+14.7%)	66.4 KiB	✅
Codex	Live turn messages	16	10	−6 (−37.5%)	21	✅
Claude	Total thread wire	11.3 KiB	13.6 KiB	+2.3 KiB (+20.1%)	15.1 KiB	✅
Claude	Thread snapshot wire	5.5 KiB	7.0 KiB	+1.6 KiB (+28.6%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	5.9 KiB	6.6 KiB	+728 B (+12.1%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	50.6 KiB	57.9 KiB	+7.3 KiB (+14.5%)	66.4 KiB	✅
Claude	Live turn messages	16	10	−6 (−37.5%)	21	✅

Baseline: 83d769f · PR result: 7862a3c · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.

• Codex decoded thread snapshot: 113.9 KiB
• Claude decoded thread snapshot: 114.6 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.

[macroscopeapp]

Approvability

Verdict: Approved at 7862a3c

Macroscope's review found this PR approvable — This is a focused desktop UI bug fix confined to titlebar drag-region hit testing. It preserves explicit no-drag controls and introduces no schema, infrastructure, security, billing, or static-analysis changes.

^{You can add or adjust custom eligibility rules. Learn more.}

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Advanced

Run ID: 64453bd3-afed-4384-a810-56b13f43757f

📥 Commits

Reviewing files that changed from the base of the PR and between f7deb75 and 7862a3c.

📒 Files selected for processing (1)

• apps/web/src/index.css

Included review availability: Your plan provides up to 10 included reviews per hour; 5 remain after this review.

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📝 Walkthrough

Walkthrough

The Electron drag-region child reset now uses initial instead of none. This preserves parent titlebar dragging while preventing child elements from creating drag rectangles.

Changes

Drag-region behavior

Layer / File(s)	Summary
Reset child drag regions apps/web/src/index.css	The direct child reset uses initial. Explicit drag and no-drag utilities retain precedence.

Priority: ➖ Normal — Impact reflects medium issue severity.

Estimated code review effort: 2 (Simple) | ~5 minutes

Severity of issue fixed: Medium

Merge Risk: ⚪ Minimal · up to 7862a

Desktop titlebar children regain normal pointer interaction while titlebar dragging and explicit drag controls remain preserved. No current merge-blocking risk is identified.

Suggested reviewers: bil0000, maria-rcks, t3dotgg

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 2 functions across 1 files. (1 skipped: 1…	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	The CSS change directly addresses issue [#10661] by preventing inherited drag-region rectangles from covering the sidebar control while preserving titlebar dragging and explicit no-drag utilities.
Out of Scope Changes check	✅ Passed	The provided changes are focused on restoring interactive hit targets within Electron drag regions. No unrelated code changes are identified.
Title check	✅ Passed	The title clearly identifies the desktop fix and the restoration of layout control hit targets.
Description check	✅ Passed	The description clearly explains what changed, why the change is needed, the interaction impact, validation performed, and the linked issue. It does not reproduce the template headings or include the …

Full details: Docstring Coverage

Explanation

Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 2 functions across 1 files. (1 skipped: 1 unsupported.)

• Fix all pre-merge checks with AI

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix-layout-control-hit-targets

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